Two-cycle internal-combustion engine



H. R. SETZ.

TWO-CYCLE INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JULY 26,1920.

Patented Feb. 21, 1922.

4 $HEETSSHEET I.

INVENTOR HANS R SUZ p A TTORNEYS H. R. SETZ.

TWO-CYCLE INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JULY 26,1920.

Patented Feb. 21, 1922.

4 $HEETSSHEET 2.

VII/11111111111111;

F W y} 03a INVENTOR HANS R5572 ATTON H. R. SETZ.

TWO-CYCLE INTERNAL COMBUSTION ENGINE.

APPLXCATION FILED JULY 26. I920.

4 SHEETSSHEIET 3.

/N VE N TOR HANS R5572 A TTORNE Y5 H. B. SETZ.

TWO-CYCLE INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JULY 26,1920.

Patented Feb. 21, 1922.

4 SHEETS-SHEET 4- HIVEMTOR E m 5 M A H H m HANS R. SET'Z, OF MANITOWOC, WISCONSIN.

TWO-CYCLE INTERNAL-COMBUSTION ENGINE.

Application filed July 26,

To all whom it may concern:

Be it known that I, HANS R. Snrz, a citizen of the United States, residing at Manitowoc, Wisconsin, have invented a certain new and useful Improvement in Two-Cycle Internal- Combustion Engines, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to two-cycle internal combustion engines of the type wherein scavenging air is admitted to the cylinder through ports in the side wall of the cylinder located opposite the exhaust ports, and particularly, to two cycle engines of the kind that are provided with means for supplying a supercharge of air to the cylinder at each cycle of operations of the piston in the cylinder.

In engines of the kind above referred to it is the usual. practice to so arrange the scavenging ports that in the direction of the cylinder axis said ports extend beyond the ends of the exhaust ports, or are at least as long as the exhaust ports. In order to prevent backing of the pressure from the interior of the engine cylinder into the scavenging air receiver prior to pressure discharge through the exhaust ports, control means for the scavenging ports must be provided which now customarily take the form of piston, poppet or rotary valves; either of these types of valves requires mechanical gearing for their operation. Devices have also been suggested whereby the scavenging ports are controlled automatically,

but the arrangements which have become known forthis purpose so far are so obviously dominated by the constructional forms resulting from the use of mechanically 0perated control means, or no control means at all, that the particular considerations underlying satisfactory o eration of automatic control means are great y encumbered. Thus with these devices it is physically impossible to give the automatic control means adequate form and area and their location is such as to greatly hamper the easy flow of scavenging air in uniform streams through all the ports; this results in uncer- Specification of Letters Patent. Patented Feb. 21, 1922.

1920. Serial No. 399,042.

tain action of the control means and poorly defined direction of flow as the air enters the cylinder. Not the least disadvantage of some of these devices is their inaccessibility and difliculty of manufacture.

The main object of my invention is to provide a two-cycle internal combustion engine having scavenging ports and automatic control means for same which are harmonized with each other in such a way as to fully meet all the functional requirements of such an arrangement in regard to adaptability to operating conditions, as well as ease of manufacture and supervision.

Another object of my invention is to provlde a two cycle internal combustion engine which is equipped with a scavenging air controlling means comprising a plurality of automatic control elements arranged so that one or more of said elements can be cut out of service, thus diminishing the supply of scavenging air and also varying the point at which the scavenging air 1s admitted without affecting the operation of the other control elements. Other objects and desirable features of my invention will be hereinafter ointed out.

To this end Ihave devised a two cycle internal combustion engine in which the supply of scavenging air to each cylinder is governed by a comparatively large number of valves of light weight and very small lift that respond to the slightest pressure differences practically instantaneously. Positiveness of action is enhanced by so arranging these valves that the turbulency of flow of the air, particularly in the immediate vicinity of the scavenging ports proper, is prevented, thereby making it possible to define the direction in which the air enters the cylinder by the form of the ports without having to resort to a bafile on the piston top. The requirements of most effective scavenging can best be satisfied by providing'a separate air inlet passageway for each scavenging port, said. passageways being arranged radially in the cylinder wall and leading from the outer cyllnder contour directly to the scavenging ports proper so as to insure uniformity of flow and make it possible to provide an intake area which will accommodate valves of the proper capacity. The control elements are arranged on the exterior of the cylinder either within or in close proximity to the outer ends of the air inlet passageways, and the scavenging air receiver is arran ed in proximity to said control elements 1n such a 'way as to freely conduct scavenging air to any one of the individualtintake areas around the circumference of the cylinder. Uniform and undisturbed flow of the scavenging air results from the location of these control elements in virtually individual passageways, while their close proximity to the ports proper ensures precise response to any pressure changes in the engine cylinder by virtue of the absence of large dead spaces between these ports and the elements The particular form or construction of the controlling valves is immaterial, and said valves can be arranged in various ways without departing from the spirit of my invention. In one embodiment of my broad idea herein illustrated an automatic control element is provided for each scavenging port, and in another embodiment of my invention herein illustrated each of the automatic control elements governs the admission of air to a plurality of scavenging ports. That feature of my invention which relates to the variation in the supply of the scavenging air admitted to the cylinder can also be carried out invarious ways) and While I have herein illustrated the valves in one form of m invention mounted in cages that can be a justed or moved so as to render the valves operative and .inoperative, I wish it to be understood that my broad idea contemplates the use of any means whereby one or more of the control elements can be rendered operative or inoperative without affecting the operation of the remaining control elements.

Figure 1 of the drawings is a vertical sectional view of one cylinder of a two 0 ole in.-

ternal combustion engine constructe in ac: cordance with my nvention.

Figure 2 is a horizontal sectional view, taken on a horlzontal plane passing through the scavenging ports and the exhaust of the cylinder shown in Fi re 1.

Figure 3 is a detail horizontal sectional view of one of the scavenging air controlling elements.

ports Figure 3 is a vertical sectional view of a;

cage provided with a plurality of valves.

Figure 4 is a vertical sectional view, illustrating another form of my invention. 1 Y Figure 5 is a horizontal sectional view. takenon a horizontal plane passing through the scavenging ports and exhaust ports of the cylinder shown in Figure 4; and

Flgure 6 is adetailed sectional vie-w of one of the scavenging air controlling elements, taken on the line 6-6 of Figure 4.

In the form of my invention -shown in with exhaust ports 2 and a single row of.

scavenging ports 3 whose upper ends terminate alt a point higher than the upper ends of the exhaust ports 2, as shown in Figure 1. The portion ofthe cylinder A in which the ports 2 and 3 are formed is surrounded by abelt or substantiall ring-shaped member B that is provided with radially-disposed passageways 4 shown in Figure 2 through which the-scavenging air is supplied to the scavenging ports 3 from a scavenging air reservoir 5 preferably formed by a hollow space in the supporting member'l which receives the cylinder A. The belt B is also provided with a assageway 6 that communicates with the exliaust ports 2 in the cylinder and through which the exhaust gases escape to the atmosphere. Interposed between the scavenging air reservoir 5 and the scavenging ports 3 are automatic controlling elements C which referably consist of spring pressed valves ight in weight and of relatively great area which are of such design that they will open and close quickly and without subjecting said valves to excessive wear. In the engine shown in Figures 1 to 3 acontrolling element is provided for each of lengtha's to completely cover the passage way 8 in the cage 7 and said passageway 8.

is preferablyof substantiallythe same form as-the scavenging port 3 with which it cooperates. The valve G is normally held seated against a .flat, vertically-disposed. .valve seat 9 on the cage 7 and is free to move inwardly away from its seat sov as to permit the scavenging air to pass from the reservoir 5 through the passageway 8 and lateral branches 8 to the scavenging port 3 with which said valve is associated, said valve being prevented from moving vertically or s'idewise bymeans of guiding surfaces on the valve cage 7 The means used in the form of my invention shown in Figuresl to 3 for holding the valve C seated consists of coiled expansion springs 10 that are arranged between said valve and a member 11 arranged in parallel relation to the valve and'connected to the cage 7 by screws or other suitable fastening devices 12. The cage 7 is arranged in one of the apertures 4 in the belt B and is connected to said belt byfastening devices 13, as shown in Figure 31. If desired, each of the cages can be provided witha plurality of valves, as shown in Figure 3, so as to get as large an area the supply of scaven as possible and at the same time reduce the lift of the valves sufliciently to insure quickness in action and quietness in operation.

The action of the scavengin air controlling elements C is as follows: an the downward stroke of the piston in the cylinder A said piston first uncovers the upper end portionsof the scavenging ports 3. Since the pressure prevailing in the cylinder at that moment may run as high as forty pounds per square inch, said pressure will be immediately transmitted to the air contained in the scaveng ng ports 3, but it cannot go farther than the controlling elements C, which, acting as check valves, prevent the transmission of this pressure into the scavenging air reservoir 5 in which the pressure of the scavenging air is in the neighborhood of five pounds per square inch, or less. As the, piston continues its downward travel, it uncovers the exhaust ports 2, thus causin an immediate and energetic drop of pressure out through the discharge passageway 6, the pressure in the cylinder approaching that of the atmosphere after a very short distance of travel of the piston. A pressure difference between the scavenging air reservoir 5 and the interior of the cylinder A is thus produced which causes the valves C, which are Only lightly pressed against their seats by the springs 10, to lift, thereby admitting scavenging air into the cylinder throughthe ports 3. The valves C being made in the form of flat, thin strips of steel or other suitable material, are extremely light, and each valve covers a comparatively large port area, only a small lift of the valves C is required in order to produce a large passageway for the inflowin scavenging air. The action of the valves is therefor quick, responding to the slightest pressure difference, and the low lift and light weight of said valves insure quietness of operation and long life, two features which are essential to an automatically operating mechanism for controlling ing air to an internal combustion engine. 33y making the valves C substantially rectangular-shaped in outline and arranging them approximately vertically so they will conform in proportion as well as location as closely as possible with the scavenging ports 3, it is possible to provide within the rather limited available space a sufiicient number of valves or controlling elements to obtain as large a passageway through the valve cages as is provided in the scavenging ports themselves.

The particular form or construction of the valves C is immaterial, so far as my. broad idea isconcerned, and therefore, .I wish it to be understood that my invention is not limited to an engine of the particular construction above .described. The essential thing is that the. scavenging air be conducted to the scavenging ports in the inner wall of the cylinder through individual radially-disposed passageways and that automatic control elements be arranged between said passageways and an air receiver of any suitable form which surrounds the section of the cylinder in which said radially-disposed passageways are formed.

As previously stated, one object of my invention is to provide a two-cycle internal combustion engine that is equipped with automatic control,elements for the scavenging air arranged in such a manner that one or more of said control elements can be rendered inoperative without affecting the operation of the remaining control elements. Under many operating conditions, particularly in marine service, an engine having the characteristic above referred to is highly desirable, as it permits the amount of scavenging air admitted to the cylinder 'to be reduced and also makes it possible to admit the scavenging air to a certain portion of the cylinder. Various means can be used for enabling the individual control elements to be rendered operative or inoperative independently of each other, and in Figures 4, 5 and 6 of the drawings I have illustrated one way of accomplishing this result, but I wish it to be understood that various other means could be used for accomplishing this purpose without departing from my invention. The engine shown in Figures 4, 5 and 6 differs from theengine illustrated in Figures 1 and 2,'in that the automatic controlling elements are so arranged that each of said elements governs the admission of scavenging air to a plurality of scavenging ports in the cylinder. The cylinder A is mounted upon instead of inside of the supporting member 1 of the frame of the engine, and it is surrounded adjacent its lower end by a belt portion B provided with a number of vertically-disposed, cylindrical valve cages 7", each of which is equipped with a controlling valve C that governs the passage of air from the scavenging reservoir 5 to two separate and distinct scavenging ports 3 in the cylinder. If the cylinder is provided with eight scavenging ports, as shown in Figure 5, sevenvalves C"will be sufficient for controlling the admission of the scavenging air to the cylinder through said ports. The valve cages 7 a are arranged in vertically-disposed bores or openings in the belt portion B and are retained in position by a member 14 that extends over the upper ends of said cages, asshown in Figure 4. Each of said cages is provided at one end, preferably at its upper end with an extension 15 of non-circular shape in cross section by which the cage may be turned or rotated with relation to the belt portion B in which it is mounted. The cages 7 each have a center passageway 8 and two side passageways or lateral branches 8, as shown in Figure 5, and said cages are equipped with flat leafsprings 11 for holding the valves C seated. If it is desired to reduce the amount of scavenging air admitted into the cylinder and also localize the admission of such scavenging air, the proper automatic scavenging air control element or elements can be rendered inoperative without stopping the engine, by simply turning the cage of said controlling element into such a position that the lateral branches 8 of same through which the scavenging air is admitted to the cylinder will be closed by a portion of the side wall of the cylindrical seat in which said cage is mounted. While I have herein illustrated my invention embodied in an. engine of the so-called single acting type, it is applicable to double acting. two cycle engines, wherein the exhaust and scavenging ports of a cylinder are located at the middle of the cylinder so as to serve either end of the cylinder.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A two-cycle internal combustion engine having a cylinder provided with exhaust ports and scavenging ports, a plurality of separately removable valve cages arranged around the outer circumference of the cylinder, and automatically operating valves in said cages for controlling thelsupply of scavenging air to the cylinder.

2. A two-cycle internal combustion engine provided with a cylinder having exhaust ports and scavenging ports, a separate scavenging air passageway in the wall of the cylinder for each of said scavenging ports, and automatic valves for governing the admission of air to the cylinder through said passages.

3. A two-cycle internal combustion engine provided with exhaust ports, scavenging ports, radially-disposed scavenging air passages in the side of the cylinder corresponding in number to the exhaust ports andleading directly from same to a source of supply of compressed air, and automatic valves for permitting air to pass from the source of supply directly into the cylinder through said passages.

4. A two-cycle internal combustion engine,

comprising la cylinder provided with e-xhaust ports, scavenging ports forming substantially radial passages between the in terior and the exterior of the cylinder, and automatic means arranged adjacent the outer ends of said passages to control the admission of scavenging air to the cylinder.

5. A two-cycle internal combustion engine havinga cylinder provided with exhaust ports and individual scavenging ports, said scavenging ports leading from the exterior directly into the interior of the cylinder without intercommunication between one another, and automatic means to control the admission of scavenging air to said ports. 6. A two-cycle internal combustion engine, comprising a cylinder provided with scavenging ports, a scavenging air reservoir extraneous to said cylinder, and a plurality of automatic valves to control communication between said reservoir and scavenging ports, said valves being mounted in separately removable cages.

7. A two cycle internal combustion engine, comprising a. cylinder provided with scavenging ports, a plurality of reciprocating controlling valves for governing the admission of scavenging air to the cylinder through said ports, each of said valves consisting of a member formed from a plate or thin strip of material, and a resilient means separate and distinct from said member for holding it seated.

8. A two cycle internal combustion engine, comprising a cylinder having scavenging ports formed in the side wall of same, and automatic valves arranged at a point outside of the cylinder in approximately parallel relation to the side wall of the cylinder and adapted to open automatically and admit scavenging air to the cylinder when the pressure'in the cylinder drops below a certain degree.

9.A two cycle internal combustion engine, comprising a cylinder provided at its side wall with scavenging ports, and a plurality of automatic, light 'weight valves arranged outside of the cylinder in approximately narallelrelation to the side wall of the cylinder, and conforming in general outline to the shape of said scavenging ports for governing the admission bf the scavenging air to the cylinder through said ports.

10. A two cycle internal combustion engine having a cylinder provided in its side wall with a scavenging port, a valve cage arranged outside of the cylinder and provided with a scavenging air passageway of substantially the same shape and size as said scavenging port, and an automatic valve in said cage for governing the admission of scavenging air to the cylinder consisting of a reciprocating member disposed approximately parallel tothe side wall of the cylinder.

11. A two cycle internal combustion engine provided with scavengingports, a plurality of automatic controlling elements for side wall with scavenging ports, an automatic controlling means for said ports consisting of a plurality of valve cages arranged outside of the cylinder and each equipped with a spring-pressed valve that controls a passageway in the cage of substantially the same area as one of the scavenging ports of the cylinder.

'13. A two cycle internal combustion engine, comprising a cylinder having exhaust ports and scavenging ports whose upper ends terminate at a point higher than the upper ends of the exhaust ports, a belt extending around the portion of the cylinder in which said' ports are formed, and a plurality of cages in said belt equipped with automatic controlling elements that govern the admission of scavenging air to the cylinder through said scavenglng ports.

14. A two cycle internal combustion engine, comprising a cylinder having exhaust ports and scavenging ports whose upper ends terminate at a point higher than the upper ends of the exhaust ports, a belt extending around the portion of the cylinder in which said ports are formed, and a plurality of cages in said belt equipped with automatic controlling elements, for governing the admission of the scavenging air to the cylinder, each of said cages being provided with an air passageway of approximately the same cross-sectional area as one of the scavenging ports, and a springpressed means that opens "automatical y when the pressure in the cylinder drops below a certain point.

i 15. A two cycle internal combustion engine, comprising a cylinder provided in its side wall with exhaust orts and'scavenging ports, a belt surrounding the portion of the cylinder in which said ports are formed and having a plurality of openings which communicate with a scavenging air reservoir, separately removable valve cages-ar ranged in said openings, and an automatic valve mounted in each of said cages.

16. A two cycle internal combustion engine, comprising acylinder provided in its side wall with exhaust ports and scaven 'ng ports, a belt surrounding the portion 0 the cylinder in which said ports are formed, a plurality of valve cages arranged in said belt, and an automaticvalve in each of said cages arranged substantially parallel to the side wall of the cylinder.

17. A two cycle internal combustion en-' gine havinjg'a cylinder provided in its side wall with a-scaven ing port, a valve cage arranged outside of the cylinder and provided with a center air passageway of substantially the same size and shape as said' port, lateral branches leading from said passageway, an automatic valve in said cage that controls the passage of the air through said lateral branches, and a resilient means that backs up said valve and holds it seated over said center passageway.

18. A two cycle internal combustion engine provided with a plurality of automatic valves for controlling the admission of scavenging air to the cylinder, and means for enabling any of said valves to be cut out of service or rendered inoperative while the engine continues in operation without affecting the operation of the other valves.

19. A two cycle internal combustion engine, comprising a cylinder provided with scavenging ports, a plurality of automatic valves for governing the admission of scavenging air to the cylinder through said ports, and means whereby any one of said valves may be rendered inoperative without rendering the remaining valves inoperative.

20. A two cycle internal combustion engine,-- comprising a cylinder, scavenging ports formed in'the side wall of same, automatic valves for controlling the admission of scavenging air to the cylinder through said ports, and adjustable members that carry said valves and adapted to be moved independently of each other so as to render one valve inoperative without affecting the operation of the remaining valves.

21. A two-cycle internal combustion engine, comprising a cylinder provided in its side wall with scavenging 'orts, automatic valves for governing the a mission of scavenging air from a supply reservoir to said ports, and cagesv for sa1d valves that are adapted to be .moved when it is'desired to render one of said valves inoperative with able cages for said valves arranged outside of the cylinder and ads. ted-to be turned independently of each 0t er for the purpose described.

24. A two cycle internal combustion engine, comprising a cylinder provided in its side. wall withexhaust ports and scavenging ports, a belt surrounding the portion of the cylinder in which said ports are formed, a plurality of cylindrical shaped, adjustable valve cages rotatably mounted in said belt, and anautomatic valve combined with each ofsai'd cages.

25. A two-cycle internal combustion engine, comprising a cylinder provided in its cages, each of said valve cages being arside Wall with exhaust ports and scavengranged at a point intermediate a pa1r of 10 ing ports, a belt surrounding the cylinder ports so that the-valve in each cage can be in which said ports are formed, a plurality used to govern the admission of scavenging of cylinder shaped valve cages arranged air to a plurality of scavenging ports in the vertically in said belt and adapted to be cylinder.

adjusted for the purpose described, and an c automatic valve combined with each of said HANS R. SETZ. 

